Shear Wave Elastography of Invasive Ductal Carcinoma: Correlations between Shear Wave Velocity and Histological Prognostic Factors.

The correlations between shear wave velocity (SWV) calculated from virtual touch tissue imaging quantification (VTIQ) technique and histological prognostic factors of invasive ductal carcinoma was investigated. A total of 76 breast tumors histologically confirmed as invasive ductal carcinomas were included in this study. SWV values were measured by VTIQ for each lesion preoperatively or prior to breast biopsy. The maximum values were recorded for statistical analysis. Medical records were reviewed to determine tumor size, histological grade, lymph node status and immunohistochemical results. Tumor subtypes were categorized as luminal A, luminal B, human epidermal growth factor receptor 2 (HER2) positive and triple negative. The correlations between SWV and histological prognostic factors were analyzed. It was found that tumor size showed positive association with SWV (r=0.465, P<0.001). Larger tumors had significantly higher SWV than smaller ones (P=0.001). Histological grade 1 tumors had significantly lower SWV values than those with higher histological grade (P=0.015). The Ki67 expression, tumor subtypes and lymph node status showed no statistically significant correlations with SWV, although triple negative tumors and lymph node-positive tumors showed higher SWV values. It was concluded that tumor size was significantly associated with SWV. Higher histological grade was associated with increased SWV. There was no statistically significant correlations between SWV and other histological prognostic factors.